HUMAN ALPHA-CRYSTALLIN-III ISOLATION AND CHARACTERIZATION OF PROTEIN FROM NORMAL INFANT LENSES AND OLD LENS PERIPHERIES

Abstract

Crystallin isolated from the peripheries of old normal or cataractous lenses appeared to be identical, consisting of 11 polypeptides, 5 B and 6 A chains. Crystallin isolated from normal 6-wk-old human lenses had only 3 major polypeptides, corresponding to B1, A1 and A2 of the old human lens protein and small amounts of some of the other components. Comparisons with bovine .alpha.-crystallin were also reported. Based on gel filtration experiments with Bio-Gel A-1.5m, 2 distinct populations of .alpha.-crystallin were found in old lens periphery, 1 containing species greater than 1.5 .times. 106 daltons and another of approximately 9 .times. 105 daltons. In the cataract preparations the higher MW fraction was predominant. This fraction was not present in young lenses.